Health effects of leaf blowers and lawn vacuums

Surprised? So were we. We knew exhaust gas is toxic and noise is annoying, but beyond that, we didn't see any other problems except for a cough lingering for a few days after blowing or vacuuming—just allergies, we presumed.

The reality is more alarming. The inescapable problem with blowers is that they blow everything on lawns, not just leaves. Lawn vacuums also stir up plumes contaminating the user's eyes, nose, lungs, ears, and clothing. What's on leaves and grass is often toxic, and what is in soil always is: no area is safe, but some are worse than others (example). Even lawn sweepers and rakes create some dust and airborne debris, and thus also pose a risk to you.

The references listed below substantiate our concerns. Most were generated by scientists, all of whom have nothing to sell, and hence no vested interest in persuading you that what is on lawns and in soil is indeed hazardous to users and their neighbors.

The irony is that people use leaf blowers and lawn vacuums to save time, but they may waste even more by triggering health problems and increasing the risk of premature death not only in the operator but others nearby because noise, exhaust, dust, and other hazards spread widely.

Minimizing future risks and focusing on immediate benefits is an example of temporal discounting. In the minds of most people, the apparent time savings from using leaf blowers instead of rakes is so alluring they opt for the blower even though it may send them to an early grave or unable to perform in the bedroom without pharmacological assistance—none happening today or anytime soon, so the generally small risk from any one usage is rounded down to zero. But just as one fast-food meal won't kill you but a steady diet of them very well may (the threshold effect, analogous to the straw that broke the camel's back), small but repeated risks can slowly add up to big problems. Leaf Magnets™ eliminate the need to trade current benefits for future risks because they outperform leaf blowers while not subjecting you to their health hazards.

Lists summarizing the health effects

Here's a summary listing problems caused or contributed to by leaf blowers, lawn vacuums, and mowers as well as sweepers and rakes to a lesser extent:

Some of the hazardous substances in soil, grass, and leaves

animal urine and feces, such as from cats, dogs, deer, birds, raccoons, rats, and mice, some of which can transmit infections, such as hantavirus, which is potentially fatal; the CDC recommends wearing a N95-rated respirator when cleaning up raccoon feces, a process that typically generates markedly less airborne emissions than blowing

decaying bodies of dead insects and animals, such as worms, birds, and snakes

pesticides, herbicides, and other chemicals

allergens such as plant pollen

dust resulting from tire wear

brake-lining dust, which may contain asbestos, which also occurs naturally in some soil

dirt (which inevitably includes metals and frequently is contaminated by heavy metals such as lead that can cause a variety of physical and cognitive effects, including impaired intelligence. Another heavy metal, cadmium, is present in soil and phosphorous fertilizers; it can cause a variety of physical effects, including cancer, kidney disease, and hair loss. Importantly, lungs absorb cadmium more readily than the gastrointestinal tract, so cadmium inhalation is especially toxic. Cadmium has a long biological half-life of 17 – 30 years, so once in the body, it takes decades to excrete half of it, therefore even tiny doses progressively accumulate. Inhaling metals, whether as dust or fumes, is often substantially more toxic than ingesting the same amount. For example, manganese is an essential trace mineral we need in our diets. Ingested in tiny amounts, it is good for us, but when chronically inhaled, it is neurotoxic because it can pass directly into the brain via olfactory pathways.)

Most people don't know about research documenting these effects, thus they never put two and two together, so if their children do not get into medical school or otherwise fail to achieve their career dreams, or if they develop health or behavioral problems, almost never is the leaf blower identified as the culprit or contributing factor.

Traffic-related air pollution linked to DNA damage in children
Comment: This translates into more health problems and shorter lives, but it's not just from automobiles; polycyclic aromatic hydrocarbons (PAHs) and other pollutants are produced by motor vehicles but the exhaust of small engines—such as those used in leaf blowers and lawn vacuums—is considerably more toxic, as documented by other references below. The irony is that in using them to save time, people risk cutting years or even decades off their lives. Not everyone succumbs to premature death, but it is impossible to escape all consequences of small-engine exhaust, such as premature signs of aging, some of which are mentioned below.

Blowback: The great suburban leaf war
Comment: Some of the many take-home messages in this superb article:
• Dr. David Lighthall said respirable road dust stirred up by leaf blowers can remain airborne for days.
• The California Air Resources Board said fine airborne particles cause 9000 premature deaths per year in California—that's like three 9/11s per year.
• After the head of a gardening crew spent eight minutes blowing, he accumulated a debris pile weighing about 12 ounces. This illustrates leaf blower inefficiency.
• Peter Kendall complained that salad greens from his organic garden are covered with dust stirred up by leaf blowers, wisely realizing that dirt contains several toxic substances. He and his wife Susan created a website (Quiet Orinda) advocating for a city ban on blowers and posted a video presenting some of their hazards.
• Attacking leaf blowers incited some of their proponents to inflict ad hominem attacks upon the Kendalls. People resort to ad hominem attacks when they cannot substantively rebut points made by their ideological opponents, substituting personal attacks on them in place of a debate of the issues.
• Orindans often worry they may lose gardeners by discussing leaf blower issues with them. As a former lawn maintenance contractor, I would have loved it if customers voiced problems and presented new solutions helping them and me. Leaf Magnets™ do exactly that.

My rake is faster than your leaf blower
Comment: Because blowers are so slow, their operators are exposed to exhaust, dust, and toxic substances in it for longer periods than they would with the efficient Leaf Magnet™ method. With it, one pass and that area is done, as opposed to leaf blowers in which areas often must be blown again as wind or the leaf blower blows leaves onto that spot again … and again. Because the airstream from blowers fans out, leaves will inevitably be blown onto previously cleared areas. The only way to minimize that is counterintuitive and awkward, making leaf blowers even more annoying to use.

Sound & Fury
Comment: According to the article, landscapers claim they must work up to 50% longer with a rake and broom instead of a leaf blower.

U.S. Geological Survey: You're Standing on It! Health Risks of Coal-Tar Pavement Sealcoat Comment: Living adjacent to coal-tar-sealcoated pavement substantially increases cancer risk; most of which stems from ingestion or inhalation of soil, since inhaled material is often swallowed. Sealcoatings easily abrade from driveways and parking lots, contaminating those surfaces and adjacent dirt with toxic particles leaf blowers can spread widely.

Counting genetic mutations predicts how soon you'll get cancer Comment: A mutation here, a mutation there: as they add up, your chance of living goes down. Unfortunately, this is just one of the cancer risks stemming from leaf blowers and lawn sweepers. Wearing a suitable mask reduces the risk to their operators, but not others who breathe in dust generated by them.

Emissions Test: Car vs. Truck vs. Leaf Blower
Comment: Despite having only ≈ 1% or less of the power of the 411-horsepower, 6,200-pound 2011 Ford F-150 SVT Raptor Crew Cab, the four-stroke Ryobi leaf blower emitted enormously more NOx, CO, and NMHC; the two-stroke leaf blower was even worse, generating more hydrocarbon emissions per season of typical use than the truck would in 20,000 – 300,000 miles (depending on yard size and leaf density).

How to save ourselves from the invisible gas choking us to death
Comment: The take-home messages:
• Millions of Europeans die per decade from air pollution with most resulting despite their air supposedly being safe.
• Strong evidence now indicates that NO2 [nitrogen dioxide] is itself harmful.
• Air pollution likely heightens the risk of autism, dementia, diabetes, and other problems.
• Researchers found myriad small iron particles in brains, likely from engine exhaust.

Heavy metals: Environmental heavy metals
Comment: The take-home messages:
• Use of leaded gasoline in North America largely ceased by 1996 but soil adjacent to roads built before then is still contaminated with lead.
• Researchers found a significant correlation between use of leaded gasoline and violent crime.
Considering the latter: because major cities had a higher density of leaded gasoline use, it isn't surprising that their violent crime rates were higher.

Light rain can spread soil bacteria far and wide, study finds
Comment: The take-home messages:
• Researchers found that raindrops produce a spray of mist (aerosols), each laden with up to several thousand soil bacteria.
• Wind can further spread airborne bacteria, enabling them to travel considerable distances, eventually settling to colonize distant areas.
Leaf blower air velocity can exceed 200 mph, so they have markedly more potential to create mists from blowing leaves wetted by rain or dew. To illustrate this, we put blue food dye on grass that was blown by a leaf blower, which sprayed mist onto downstream paper (see below). In addition to the distinct spots, note the diffuse bluish haze especially concentrated near the upper center; that resulted from an aerosolized mist of countless tiny droplets—ones ideally suited for long-distance spread. The direct blast can travel many feet, but once airborne, wind can carry it hundreds or thousands of feet.

CDC: Emergence of Cryptococcus gattii--- Pacific Northwest, 2004--2010
Excerpt: “C. gattii is an emerging infection in the United States. C. gattii appears to differ from its sibling species, C. neoformans, both in its clinical aspects (e.g., less responsive to antifungal drugs and more likely to cause tumor-like lesions called cryptococcomas) and its ecologic niche … In addition, whereas the primary risk factor for C. neoformans cryptococcosis is severe immunosuppression (e.g., from HIV infection), risk factors for C. gattii infection in the United States appear to include both immunocompromise and exposure to specific regions of environmental fungal colonization … Many cases of C. gattii infection are likely not recognized because distinguishing between C. gattii and C. neoformans requires plating on differential media not routinely available in clinical microbiology laboratories; therefore, many cryptococcal infections are never speciated. … Fungal spores are known to colonize the nasal cavity and spread to other body sites, causing meningitis, pneumonia, and the development of lung, brain, or muscle cryptococcomas …”

CDC: Anthrax
Excerpt: “People get infected with anthrax when spores get into the body. … This can happen when people breathe in spores, eat food or drink water that is contaminated with spores, or get spores in a cut or scrape in the skin. It is very uncommon for people in the United States to get infected with anthrax.”
Comment: But it happens, and if it happens to you, its rarity is no consolation.

Investigation of Inhalation Anthrax Case, United States
Excerpt: “Inhalation anthrax occurred in a man who vacationed in 4 US states where anthrax is enzootic. Despite an extensive multi-agency investigation, the specific source was not detected, and no additional related human or animal cases were found. Although rare, inhalation anthrax can occur naturally in the United States.”

Anthrax in the United States: Respiratory, Inhalational, or Pulmonary Anthrax: “is contracted by breathing in the anthrax spores. It has similar symptoms to the cold and flu for the first few days—a sore throat, muscle aches, and fever are often common. However, the disease then deviates, resulting in acute breathing difficulty and shock, which is often fatal. Untreated cases have a 100% mortality rate.”

Landscapes Tainted by Asbestos
Comment: The take-home messages:
• Naturally occurring asbestos has been found in locations throughout the United States.
• Minerals physically similar to asbestos, such as erionite, can also form needlelike structures that heighten the risk of mesothelioma.
• Some California residential developments were built on soil containing asbestos; such fibers were found blowing around those communities.
• Human harm resulted from considerably smaller amounts of asbestos than were previously assumed to be dangerous.

Technology Can't Solve Every Problem, but It Sure Helps With This One (Leafblower Dept)
Comment: Electric blowers are quieter, but the inescapable problem with all leaf blowers is that they blow. Operators could reduce risks to themselves by wearing goggles, a respirator, earmuffs, and covering all skin with clothing, but doing that would frequently make blowing uncomfortably warm, even dangerous during hot weather. Furthermore, it does nothing to shield others from airborne debris stirred up by leaf blowers. Mr. Fallows touts the electric Stihl BGA 100, but even in what Stihl terms the “Boost Mode,” it is less than half as powerful as some gas blowers, none of which can equal the performance of Leaf Magnets™. Cost and battery capacity limiting run time are two more strikes against electric blowers.

Association between seropositivity for Toxoplasma gondii, scholastic development of children and risk factors for T. gondii infection
Comment: The take-home messages:
• Toxoplasma oocysts are usually acquired from soil.
• Infected men are more distrustful, aggressive, and apt to break rules; infected women more likely to feel a need to abide by them yet are paradoxically uninhibited.
• When infected, both sexes exhibit slowed reaction time and more difficulty maintaining concentration.
• Infected children scored less well on the Scholastic Performance Test with math giving them the most difficulty. Hence avoiding leaf blowers and lawn vacuums is occupationally relevant for those seeking careers demanding brainpower.
• Most lawn and exposed soil samples were contaminated.
Previously, T. gondii infection was thought to generally endanger pregnant women and people with impaired immunity, such as diabetics or those with HIV; infections in others was thought to be typically asymptomatic—that is, without symptoms.

Influence of latent Toxoplasma infection on human personality, physiology and morphology: pros and cons of the Toxoplasma-human model in studying the manipulation hypothesis
Comment: The take-home messages:
• Toxoplasma gondii infection was previously assumed to be asymptomatic but actually produces significant effects in humans, such as by increasing reaction time, which explains why infected people have a higher probability of traffic accidents.
• Latent infection with Toxoplasma gondii is associated with immunosuppression, which may explain why mothers of children with Down syndrome have a very high prevalence of toxoplasmosis.
• Male students infected with Toxoplasma gondii are approximately 3 cm taller and have faces perceived by women to be more masculine and dominant: effects that may be caused by increased testosterone.
• Toxoplasma gondii infection is associated with the initiation of more severe schizophrenia.
• Dozens of studies have demonstrated a link between toxoplasmosis and schizophrenia.

Can the common brain parasite, Toxoplasma gondii, influence human culture?
Comment: The take-home messages:
• Toxoplasma gondii manipulates human personality.
• Most infected people initially experience only mild flu-like symptoms, but fetal infection can produce devastating effects.
• After the initial infection, Toxoplasma parasites become largely dormant in tissues including the brain.
• The seroprevalence of Toxoplasma gondii exhibits substantial geographic variation that may explain behavioral differences in people from different areas.
• Toxoplasma gondii infection is associated with increased neuroticism and proneness to guilt; infected women are more rule-conscious, conforming, and staid; infected men are less intelligent, more rigid, more emotionally reactive, more changeable, more affected by feelings, more easily upset, and less emotionally stable.
• Toxoplasma gondiioocysts live longer in low-altitude areas with higher humidity, especially those at mid-latitudes with infrequent freeze-thaw cycles.
• People working with soil are more likely to ingest Toxoplasma gondii oocysts.

Toxoplasma – the brain parasite that influences human culture
Comment: The take-home messages:
• Toxoplasma gondii carriers are more likely to exhibit long-term personality changes. Effects differ in men and women but both are more neurotic.
• Countries with a higher prevalence of Toxoplasma gondii infection more often have (1) more pronounced differences in gender roles with more focus on ambition, work, and money instead of people and relationships, (2) greater risk aversion, (3) a tendency to embrace strict regulations and rules.